Na+ Cl- ion pair association in water-DMSO mixtures: Effect of ion pair model potentials

Journal of Chemical Sciences

ANUPAM CHATTERJEE¹  B L TEMBE¹  S C TIWARI¹  ATANU SARKAR¹ 

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关键词: Potential models;    potentials of mean force;    residence times;    running coordination numbers.;   

DOI  :  

来源: Indian Academy of Sciences

【 摘 要 】

Potentials of Mean Force (PMF) for the Na+ Cl- ion pair in water–dimethyl sulfoxide (DMSO)mixtures for three DMSO mole fractions have been computed using constrained Molecular Dynamics (MD)simulations and confirmed by dynamical trajectories and residence times of the ion pair at various inter-ionicseparations. The three ion-ion direct potentials used are 12-6-1, exp-6-1 and exp-8-6-1. The physical picturethat emerges is that there is a strong contact ion pair (CIP) and strong to moderate solvent separated ion pair(SSIP) in these solutions. Analysis of local ion clusters shows that ions are dominantly solvated by watermolecules. The 12-6-1 potential model predicts running coordination numbers closest to experimental data.

【 授权许可】

Unknown